;************************************************************************
;*									*
;*	program to format a microdecision drive b head 0 track over	*
;*	and over again for troubleshooting purposes			*
;*	BY RONALD E. JACOBS  JUNE 15, 1986				*
;*									*
;************************************************************************

	BDOS	EQU	5


	.Z80

start:	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,4Dh		;NEC 765 format a track COMMAND CODE
	OUT	(0FBh),A	;SEND format a track cmd TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,01		;side 0,  drive 1
	OUT	(0FBh),A	;SEND SECOND COMMAND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,03		;N: bytes per sector (03=1024 selected)
	OUT	(0FBh),A	;SEND SECOND COMMAND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,04		;SC: sectors per track
	OUT	(0FBh),A	;SEND SECOND COMMAND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,0f0h		;GPL: gap three
	OUT	(0FBh),A	;SEND SECOND COMMAND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,99h		;D: filler byte
	OUT	(0FBh),A	;SEND SECOND COMMAND BYTE TO NEC 765 DATA PORT

	ld	a,0
	ld	(sectr),a	;initialize sector number
	call	chrn		;supply C, H, R, N for each sector on the track
	call	chrn		;	there are five sectors
	call	chrn
	call	chrn
	call	chrn

	call rdrdy		;there are 7 result bytes to be read
	call rdrdy		;2
	call rdrdy		;3
	call rdrdy		;4
	call rdrdy		;5
	call rdrdy		;6
	call rdrdy		;7

	jp	start		;format the track all over again


chrn:	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,05h		;C: cylinder number
	OUT	(0FBh),A	;SEND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	LD	A,00h		;H: head number
	OUT	(0FBh),A	;SEND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	ld	a,(sectr)	;old sector number
	inc	a		;add 1 to make new sector number
	OUT	(0FBh),A	;SEND BYTE TO NEC 765 DATA PORT

	CALL	CMDRDY		;IS DATA PORT READY TO RECEIVE A COMMAND BYTE
	Ld	A,03		;03 = 1024 bytes per sector code number
	OUT	(0FBh),A	;SEND BYTE TO NEC 765 DATA PORT

	ret


;************************************************************************
;*									*
;*			SUBROUTINE CMDRDY				*
;*									*
;*	READS MICRODECISION PORT 0FAh TO GET THE STATUS OF THE NEC 765	*
;*	CONTROLLER CHIP.  THIS IS A CHECK TO SEE IF THE CHIP IS READY	*
;*	FOR THE NEXT BYTE OF THE COMMAND.				* 
;*									*
;************************************************************************
	
CMDRDY:	CALL	MDDLY		;DELAY 12.5 uS
	IN	A,(0FAh)	;READ NEC 765 STATUS PORT

	AND	11000000b	;MASK OUT SOME BITS
	CP	10000000b	;IS DATA PORT READY TO RECEIVE DATA?
	JP	NZ,CMDRDY	;LOOP UNTIL READY
	RET


;************************************************************************
;*									*
;*			SUBROUTINE RDRDY				*
;*									*
;*	READS MICRODECISION PORT 0FAh TO GET THE STATUS OF THE NEC 765	*
;*	CONTROLLER CHIP.  THIS IS A CHECK TO SEE IF THE CHIP IS READY	*
;*	FOR THE NEXT BYTE OF THE RESULT.				*
;*									*
;************************************************************************

RDRDY:	CALL 	MDDLY		;DELAY 12.5 uS
	IN	A,(0FAh)	;READ NEC 765 STATUS PORT

	anä	11000000b	;savå DATÁ INPUT/OUTPUT,REQUESÔ FOÒ MASTEÒ BITS
	CP	11000000b	;IS DATA PORT READY TO SEND DATA?
	JP	NZ,RDRDY	;LOOP UNTIL READY

	call	tblpnt		;~
	push	psw		;~
	ld	e,'s'		;~
	ld	c,6		;~
	call	bdos		;~
	pop	psw		;~

	RET

;************************************************************************
;	temproarilyr for trouble reporting
;	saves the a register
;************************************************************************

tblpnt:	ld	h,a		;~save for reuse
	ld	a,' '		;prepare to print a space
	call	is09
	ld	a,h

	rlc	a		;~get upper nybble
	rlc	a		;~
	rlc 	a		;~
	rlc 	a		;~
	call	tblout		;~
				;~
	ld	a,h		;~
	call	tblout		;~
	ld	a,h		;~
	ret			;~

tblout:	and	0fh		;~mask upper four bits
	or	30h		;~make ascii digit 
	cp	3Ah		;~is it a 0-9 or A-F?
	jp	c,is09		;~it is a digit 0-9 
	add	a,7		;~make it A-F
is09:	ld	e,a		;~ready to be printed
	ld	c,6		;~bdos direct console i/o
	push	hl		;~
	call bdos		;~^^^^^^^^for troubleshooting^^^^^^^^^^^
	pop	hl		;~
	ret			;~


;************************************************************************
;*									*
;*			SUBROUTINE MDDLY				*
;*									*
;*	DELAYS 12 uS.  12uS IS THE MINIMUM TIME REQUIRED BETWEEN BYTES 	*
;*	BEING OUTPUT TO THE NEC 765.  					*
;*		12.5uS = (50 CYCLES)/(4 MHZ)				*
;*									*
;************************************************************************

MDDLY:	EX	(SP),IX		;23 CLOCK CYCLES TO EXECUTE THIS INSTRUCTION
	EX	(SP),IX		;23 MORE CLOCK CYCLES
	RET			; 1 CLOCK CYCLE FOR RET (3 CYCLES FOR CALL)  


sectr:	ds	1		;sector number being formated

	end